Finding the right powder for your load can involve compromises. Powder burn rate, metering, and temperature sensitivity are examples of variables that may translate to compromises based on your reloading equipment and load/cartridge.

With newer powders like Winchester StaBALL 6.5, those compromises are becoming less of an issue. In this article, we’ll explore this recent addition to the Winchester powder lineup.

Disclaimer

Ultimate Reloader LLC / Making with Metal Disclaimer: (by reading this article and/or watching video content you accept these terms)

• The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only.
• Do not attempt any of the processes or procedures shown or described on this website.
• All gunsmithing procedures should be carried out by a qualified and licensed gunsmith at their own risk.
• Do not attempt to repair or modify any firearms based on information on this website
• Ultimate Reloader, LLC and Making With Metal can not be held liable for property or personal damage due to viewers/readers of this website performing activities, procedures, techniques, or practices described in whole or part on this website.
• By accepting these terms, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this website.

About StaBALL 6.5

From the Winchester StaBALL 6.5 Product Page:

Winchester StaBALL 6.5 is the world’s first temperature-insensitive BALL Powder, stable in extreme-hot or -cold conditions. It provides optimal loading density in cartridges appropriate for the burn speed, which is ideal for 6 Creedmoor, 6GT, 6.5 Creedmoor, 7MM-08, 270 Winchester and many more. Typical of a ball powder, precise metering contributes to improved velocity and pressure standard deviations, ingredients that are paramount to match grade accuracy! This REACH-compliant, “environmentally green” propellant has copper fouling reducer additives, meaning longer durations of competition and field shooting without having to clean the bore. Precision accuracy throughout the match! Velocity levels obtainable, depending on the cartridge, are 30-200 fps greater than other propellants in its class. Stability, Precision and Speed, says Winchester StaBALL 6.5 is the “Best of the Best”!

Burn Rate

Winchester StaBALL 6.5 is on the slower-end of the relative burn rate chart for Creedmoor-class powders. This should make it ideal for both mid-weight and heavy-weight bullets in each Creedmoor cartridge application.

Here we have the approximate burn rate range for Creedmoor class cartridges, and Winchester StaBALL 6.5 in the red rectangle:

Informal Density Testing

One of the things I found interesting for Winchester StaBALL 6.5 was how it is more dense compared to some of the other powders I’ve been using for Creedmoor cartridge loading recently. So I did some “informal” testing with a non-precision scale, and a measuring cup. Here’s the calculations I performed:

This shows that H-4350 is *about* 5% more dense compared to Vihtavuori N555 (I tested this powder recently), and Winchester StaBALL 6.5 is *about* 10-11% more dense than H-4350. Depending on the load you’re working up, this can be beneficial for more velocity, and for more consistent velocity.

*Note: These results were non-scientific. There are *many* factors that have an effect on density measurements and calculations including lot-to-lot variations, how the powder is poured into the container, and more. The data I calculated is however consistent with trends in data I received from various powder manufacturers first-hand.

Granule Characteristics: Some Creedmoor-Class Powders Compared

For this powder story, I decided to compare a few Creedmoor-Class powders under the microscope! Here are the powders I chose:

From left to right we have: Winchester StaBALL 6.5, Hodgdon H-4350, and VihtaVuori N555.

For this examination, I used a 400 power WiFi microscope as seen here:

Here’s a closeup of the Microscope view with  Machinist’s scale (1/64″ increments):

Above you can see from left to right Winchester StaBALL 6.5, Hodgdon H-4350, and VihtaVuori N555 (same ordering as picture with powder kegs).

Using the scale, the approximate dimensions for the powders (diameter or length as shown above):

Powder	Length/Dia (in)
N555	0.0430
H-4350	0.0547
STABALL 6.5	0.0313

I thought the density numbers would trend with powder granule size (inversely proportional) but that was not the case when we look at the powder stick length for H-4350 and for N555! Interesting…

StaBALL Test 1: 25 Creedmoor

When I started my load development for the 25 Creedmoor- I thought to myself: I’ve got to try StaBALL 6.5 with 25 Creedmoor and the Blackjack ACE 131 grain bullet! And that’s exactly what I did here.

Here’s the velocity data I collected for the loads tested: (3-shot strings)

For comparison, here is the load data from my 25 Creedmoor Load development using H-4350:

As you can see here, we got higher velocities with the StaBALL 6.5.

StaBALL Test 2: 6.5 Creedmoor

For 6.5 Creedmoor, I tested two bullets, Hornady’s 135 grain 6.5mm A-Tip bullet, and Berger’s 140 grain 6.5mm Hybrid.

Velocities here were very good, both in magnitude and consistency: (3-shot strings)

Those SD and ES numbers are OUTSTANDING for a factory rifle (which I’ve accurized, but haven’t enhanced the firing pin assembly). Accuracy was also great, with groups down to 3/8″.

Conclusion

Winchester StaBALL 6.5 is now on my short-list for loading the “Creedmoor Class” of cartridges. Since I have rifles in 6mm Creedmoor, 25 Creedmoor, and 6.5 Creedmoor, this will keep me busy for a LONG time.

My next loads with StaBALL 6.5 will involve heavy-for-class bullets (like the Berger 153.3 grain 6.5mm bullet for 6.5 Creedmoor).

Don’t miss out on Ultimate Reloader updates, make sure you’re subscribed!

Thanks,
Gavin